1. Field of the Invention
The present invention relates to a heat-dissipating device and, more particularly, to a phase change evaporator using a phase-changeable coolant for heat dissipation and a phase change cooling device using the phase change evaporator.
2. Description of the Related Art
As we know, heat is generated by electronic devices when the electronic devices are operating. To lower the chance of irregular operation or damage to an electronic device arising from an overheat condition, by and large, a cooling device is installed at a heat-generating source of the electronic device to absorb heat generated by the heat-generating source to achieve a cooling purpose.
Conventionally, each phase change cooling device includes an evaporator and a condenser. A coolant output pipe and a coolant return pipe are connected in series to the evaporator and the condenser to form a closed coolant circulation loop with an adequate amount of coolant filled inside the coolant circulation loop. Thus, the evaporator is used to absorb heat generated by an electronic device to convert coolant in the evaporator from a liquid state to a gaseous state. The gaseous coolant flows to the condenser through the coolant output pipe for heat dissipation by virtue of an expanding cooling surface area of the condenser, such that the gaseous coolant is converted back to the liquid state. The liquid coolant then returns to the evaporator to resume heat absorption through the coolant return pipe.
As the evaporator only provides a space for the coolant to be converted from a liquid state into a gaseous state and as the entire cooling device utilizes the phase change of the coolant and the circulation of coolant between the evaporator and the condenser, the resultant cooling efficacy of the cooling device fails to be satisfactory.